Preheat the oven to 325 degrees and butter and flour a 9 by 12 inch baking pan. Line the base of the pan with parchment paper. Combine the chocolate, butter, coffee, and salt in the top of a double boiler and, over simmering water, melt the chocolate, stirring occasionally.

In a large mixing bowl, combine the sugar, eggs, and vanilla and whisk until smooth. Add the melted chocolate mixture and continue whisking until well combined. Fold in the flour until you can't see any traces of white, but do not overfold. Gently fold in the pecans. Scoop out into the prepared pan and spread and jiggle the pan until the batter finds its level.

Bake for about 35 minutes, or until a toothpick inserted into the center of the pan comes out clean. Set the pan on a rack to cool for 1 hour. Run a knife around the edge of the pan to loosen, then cut into squares as desired.